A YELLOW weather warning for rain and thunderstorms has been issued for Derry and the rest of the North of Ireland on Friday.
The Met Office said there is a small chance of flooding at homes and businesses, as well as a chance of deep floodwater causing danger to life.
Delays and cancellations to train and bus services can also be expected in flood-hit areas.
Spray and flooding could lead to difficult driving conditions and road closures.
A Met Office spokesperson said: “A band of heavy rain, with the possibility of some very heavy bursts, will move northwards during Thursday night and Friday.
“Within this band 10-15 mm is widely expected, however some places could see as much as 30 mm in just a few hours.
“Once the rain has cleared scattered showers and thunderstorms are expected to develop, particularly during Friday.
“Many places will miss these, but where they do occur 10-20 mm is possible in one hour, with perhaps 30 mm in a few hours.”